• IMMUNE NETWORK
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• v.11 no.5
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• pp.268-280
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• 2011

Background: Dengue virus, which belongs to the Flavivirus genus of the Flaviviridae family, causes fatal dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) with infection risk of 2.5 billion people worldwide. However, approved vaccines are still not available. Here, we explored the immune responses induced by alternating prime-boost vaccination using DNA vaccine, adenovirus, and vaccinia virus expressing E protein of dengue virus type 2 (DenV2). Methods: Following immunization with DNA vaccine (pDE), adenovirus (rAd-E), and/or vaccinia virus (VV-E) expressing E protein, E protein-specific IgG and its isotypes were determined by conventional ELISA. Intracellular CD154 and cytokine staining was used for enumerating CD4+ T cells specific for E protein. E protein-specific CD8+ T cell responses were evaluated by in vivo CTL killing activity and intracellular IFN-${\gamma}$ staining. Results: Among three constructs, VV-E induced the most potent IgG responses, Th1-type cytokine production by stimulated CD4+ T cells, and the CD8+ T cell response. Furthermore, when the three constructs were used for alternating prime-boost vaccination, the results revealed a different pattern of CD4+ and CD8+ T cell responses. i) Priming with VV-E induced higher E-specific IgG level but it was decreased rapidly. ii) Strong CD8+ T cell responses specific for E protein were induced when VV-E was used for the priming step, and such CD8+ T cell responses were significantly boosted with pDE. iii) Priming with rAd-E induced stronger CD4+ T cell responses which subsequently boosted with pDE to a greater extent than VV-E and rAd-E. Conclusion: These results indicate that priming with live viral vector vaccines could induce different patterns of E protein-specific CD4+ and CD8+ T cell responses which were significantly enhanced by booster vaccination with the DNA vaccine. Therefore, our observation will provide valuable information for the establishment of optimal prime-boost vaccination against DenV.

• Journal of Veterinary Science
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• v.22 no.1
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• pp.8.1-8.11
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• 2021

Background: Porcine circovirus type 2 (PCV2) is an important infectious pathogen implicated in porcine circovirus-associated diseases (PCVAD), which has caused significant economic losses in the pig industry worldwide. Objectives: A suitable viral vector-mediated gene transfer platform for the expression of the capsid protein (Cap) is an attractive strategy. Methods: In the present study, a recombinant adeno-associated virus 8 (rAAV8) vector was constructed to encode Cap (Cap-rAAV) in vitro and in vivo after gene transfer. Results: The obtained results showed that Cap could be expressed in HEK293T cells and BABL/c mice. The results of lymphocytes proliferative, as well as immunoglobulin G (IgG) 2a and interferon-γ showed strong cellular immune responses induced by Cap-rAAV. The enzyme-linked immunosorbent assay titers obtained and the IgG1 and interleukin-4 levels showed that humoral immune responses were also induced by Cap-rAAV. Altogether, these results demonstrated that the rAAV8 vaccine Cap-rAAV can induce strong cellular and humoral immune responses, indicating a potential rAAV8 vaccine against PCV2. Conclusions: The injection of rAAV8 encoding PCV2 Cap genes into muscle tissue can ensure long-term, continuous, and systemic expression.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.143-149
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• 1997

Most of the current licenced hepatitis B vaccines are being produced by recombinant DNA technology in large fermentation cultures of Saccharomyces cerevisiae of yeast cells which carry the gene coded for hepatitis B virus surface antigen. These vaccines are proved very effective clinically and the immunogenicity of vaccines could be maintained for a long time under refrigeration. To develope the stabilizer that could increase the stability of hepatitis B virus vaccine which could be stored for a long period at room temperature or higher conditions, glucose, lactose and sucrose solutions in phosphate buffered saline were added into hepatitis B vaccine respectively to make 2.5%, 5%, 7.5% and 10% final concentration in vaccines. These sugar-vaccine mixtures were stored at room temperature for one month, two months and three months respectively and then inoculated into ICR mice intramuscularly. On the fourteenth day after inoculation, mice were bled and sera were tested for the evaluation of efficacies of vaccines. The results showed that 5% glucose, 7.5% lactose and sucrose increased the stability of vaccines in some degree and this method could be applied for the production of other viral vaccines and bacterial vaccines.

• Korean Journal of Veterinary Research
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• v.2 no.1
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• pp.27-36
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• 1962

Immune response to two methods of Newcastle disease virus vaccine, one inactivated and the other attenuated was observed and the data presented. (1) Administration of inactivated virus vaccine in an amount of 1.0 ml. by intramuscular route gave an appreciable immunity to Newcastle disease for a period of at least three-and-half months. (2) The chickens given attenuated virus vaccine in the drinking water produced satisfactory immunity as manifested by the fact that immunized birds showed resistance when challenged 105 days after the vaccination and maintained high degree of HI titer for a period of 75 days. (3) Vaccination with the attenuated virus vaccine in drinking water is very simple and time saving in procedure, although the duration of immunity seems to be slightly shorter than that proced by inactivated virus vaccine. The author wishes to express his appreciation, to Drs. Kyu Myung Lee, Chang Koo Lee, and Ryong Sook Kee of their suggestions and help. The author is also indebted to Dr. Chang Hi Lee, Director of Anyang Veterinary Laboratory, who allowed the use of the facilities of the laboratory, whitout which this experiment could not have been undertaken.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.116-117
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• 2002

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.997-1006
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• 2018

As shown during the 2009 pandemic H1N1 (A(H1N1)pdm09) outbreak, egg-based influenza vaccine production technology is insufficient to meet global demands during an influenza pandemic. Therefore, there is a need to adapt cell culture-derived vaccine technology using suspended cell lines for more rapid and larger-scale vaccine production. In this study, we attempted to generate a high-growth influenza vaccine strain in MDCK cells using an A/Puerto/8/1934 (H1N1) vaccine seed strain. Following 48 serial passages with four rounds of virus plaque purification in MDCK cells, we were able to select several MDCK-adapted plaques that could grow over $10^8PFU/ml$. Genetic characterization revealed that these viruses mainly had amino acid substitutions in internal genes and exhibited higher polymerase activities. By using a series of Rg viruses, we demonstrated the essential residues of each gene and identified a set of high-growth strains in MDCK cells ($PB1_{D153N}$, $M1_{A137T}$, and $NS1_{N176S}$). In addition, we confirmed that in the context of the high-growth A/PR/8/34 backbone, A/California/7/2009 (H1N1), A/Perth/16/2009 (H3N2), and A/environment/Korea/deltaW150/2006 (H5N1) also showed significantly enhanced growth properties (more than $10^7PFU/ml$) in both attached- and suspended-MDCK cells compared with each representative virus and the original PR8 vaccine strain. Taken together, this study demonstrates the feasibility of a cell culture-derived approach to produce seed viruses for influenza vaccines that are cheap and can be grown promptly and vigorously as a substitute for egg-based vaccines. Thus, our results suggest that MDCK cell-based vaccine production is a feasible option for producing large-scale vaccines in case of pandemic outbreaks.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.849-859
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• 2018

Herpes simplex virus type 2 (HSV-2) infection has been a public health concern worldwide. It is the leading cause of genital herpes and a contributing factor to cervical cancer and human immunodeficiency virus (HIV) infection. No vaccine is available yet for the treatment of HSV-2 infection, and routinely used synthetic nucleoside analogs have led to the emergence of drug resistance. The small molecule $Retro-2^{cycl}$ has been reported to be active against several pathogens by acting on intracellular vesicle transport, which also participates in the HSV-2 lifecycle. Here, we showed that Retro-2.1, which is an optimized, more potent derivative of $Retro-2^{cycl}$, could inhibit HSV-2 infection, with 50% inhibitory concentrations of $5.58{\mu}M$ and $6.35{\mu}M$ in cytopathic effect inhibition and plaque reduction assays, respectively. The cytotoxicity of Retro-2.1 was relatively low, with a 50% cytotoxicity concentration of $116.5{\mu}M$. We also preliminarily identified that Retro-2.1 exerted the antiviral effect against HSV-2 by a dual mechanism of action on virus entry and late stages of infection. Therefore, our study for the first time demonstrated Retro-2.1 as an effective antiviral agent against HSV-2 in vitro with targets distinct from those of nucleoside analogs.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.12-19
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• 2008

Varicella is a highly infectious disease caused by the varicella zoster virus. The varicella vaccine was developed by Michiaki Takahashi in Japan in 1974. Despite the worldwide distribution of efficient vaccines, varicella vaccination policy is extremely variable from country to country. Although varicella vaccine is not currently recommended for universal vaccination in Japan, most countries throughout Europe, and developing countries, it had been introduced into Korea in 1988 and 20 years have elapsed since its use. Currently, varicella vaccine has been most extensively used in the United States where routine 2-dose vaccination program has been recently implemented for children. Recent 2-dose schedule in the United States and the availability of combination measles-rubella-varicella vaccines may lead to future varicella vaccination policy changes in many countries. With this background, this article summarizes the current status of varicella vaccination policies worldwide and presents provisional updated recommendation of varicella vaccination in Korea.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.86-89
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• 2016

The Zika virus, which is a member of the flavivirus genus, poses a serious threat to humanity because there is no vaccine or cure. Zika is suspected to cause microcephaly, and it is rapidly spreading throughout parts of Brazil. Surprisingly, there are no known protein structures for the virus which are essential for drug and vaccine development. This paper investigates the Zika virus's nonstructural proteins with template-based modeling by using GalaxyTBM/Refine/SC. GalaxyDock was used to examine the effectiveness of various known serine protease inhibitors in inhibiting the Zika viral protease. In testing five inhibitors, Kunitz soybean trypsin inhibitor showed the strongest binding affinity (-10.082 kcal/mol). This paper provides a rudimentary foundation for further drug discovery research regarding the Zika virus.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.83-89
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• 1981

Japanese encephalitis has been prevalent for long time in the Far East and many patients have been reported in both South East and Mid-West Asia recently. Recently, vaccine was used in prevention of this viral disease of man which was derived from formalin inactivated virus inoculated into mouse brain, but live attenuated active vaccine for human is not developed yet. Author inoculated Japanese encephalitis virus into several cell culture strains for development of live attenuated encephalitis virus strain and the results were as follows: 1. Japanese encephalitis virus was inactivated rapidly in cell free medium at $36^{\circ}C$ and totally inactivated by 72 hours. 2. In growth curve of Japanese encephalitis virus in HeLa cell cultures, maximal multiplication of the virus was occured at 4th day and virus multiplication was continued for at least 12 days. 3. After succeeding passage of the virus in HeLa cell cultures and human esophagus epithelial cell cultures, infectivity of virus for mice was disappeared from 2nd passage in HeLa cell cultures and 3rd passage in esophagus epithelial cell cultures. 4. In inoculation to monkey kidney epithelial cells and chick embryo cell cultures, infectivity of the virus for mice was continued after 10th passages.